Jann Horn discovered that the Linux kernel mishandles mapping UID or GID ranges inside nested user namespaces in some situations. A local attacker could use this to bypass access controls on resources outside the namespace. (CVE-2018-18955)

Philipp Wendler discovered that the overlayfs implementation in the Linux kernel did not properly verify the directory contents permissions from within a unprivileged user namespace. A local attacker could use this to expose sensitive information (protected file names). (CVE-2018-6559)

Upgrade Pivotal products that use earlier versions of CF components to new Pivotal releases using new versions linked above. On the Pivotal Network product page for each release, check the Depends On section and/or Release Notes for this information.